Anti-roll bars, also known as stabilizer bars or sway bars, are used in both front and rear suspensions to reduce vehicle body lean during vehicle turns. The anti-roll bar, which twists during body lean, increases the resistance to body lean provided by the suspension springs and suspension control arms of the vehicle suspension. In addition, vehicle handling characteristics, such as understeer and oversteer, can be adjusted by changing the torsional stiffness of the anti-roll bar.
A torsionally stiff anti-roll bar is known to increase the spring rate of the suspension during road bumps encountered by only one tire, thereby removing some of the independence of an independent suspension and stiffening the ride of the vehicle. Consequently, the torsional stiffness of the anti-roll bar is typically optimally selected for a given vehicle based on the vehicle's intended handling and ride characteristics.